Earth boring apparatus



. EARTH BORING APPARATUS Filed Dec. 24. 1930 2 Sheets-Sheet 1 l l4 u l :Hlh b HIM B Clare/162 155? R.

1% z. W \A ATTORNEY.

y 1934- c. E. REED 1,956,729

AAAAAAAAAAAAAAAAAA US Patented May 1, 1934 UNITED STATES PATENT OFFICE 1,956,729 EARTH BORING APPARATUS Clarence E. Reed, Wichita, Kans assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey This invention relates to earth boring by rotary drilling and particularly to apparatus of the type which mounts at the cutting end of the bit roller cutters arranged for free rolling contact with the bottom of the hole. More specifically it concerns bit heads of one piece in which the cutters are individually mounted on spindle and shank members to form units insertable axially in the lower end of the bit head after the 0 manner disclosed in my U. S. Patent No. 1,636,665,

issued July 19, 1927. The present inventionis an improvement upon or further development of the invention set forth and claimed in the aforesaid patent. I

In bit heads of the described type in the small sizes now used for bringing in deep wells, difliculties are encountered in adequately supporting 'the cutters against side thrust and compression toward each other'under operating load and in providing shanks of adequate cross sectional area 50 positioned as not to weaken the walls of the small bit head.

One object of the invention is to improve the structure and cooperative action of one-piece bit heads having cutter units axially insertable therein and removable therefrom. Another object is to provide renewable members for supporting the side thrusts and compression strains on the cutter units. Another object is to obtain large shank bearing areas in small diameter heads without weakening the latter. Other objects will be apparent from the detailed description which follows.

The invention involves an improved socket arrangement in the lower end of the bit head to receive cutter units of novel configuration and so arranged that the base portions of the units are in abutting relation directly to take the side thrust and compression strains encountered in service. shank to be disposed inwardly toward the axis of the bit head and substantially centrally of the bit head wall on each side of the wash pipe bore. A large securing member or nut can be out the metal of the bit head at the rear of the side recess through to the wash pipe bore.

In order to illustrate the invention one concrete embodiment thereof is shown in the accompanying drawings in which:

Fig. 1 is a view partly in vertical section and partly in side elevation of a bit head having the cutter units mounted therein and ready for service;

Fig. 2 is a vertical sectional view ofthe lower The new unit permits the supporting used on the shank of the cutter unit by cutting.

end of the bit head only, the section beingtaken on the line 2--2 of Figs. 3 and 4;

Fig. 3 is a plan view of the lower end of the bit head;

Fig. 4 is a sectional view substantially on the line 4-4 of Fig. 2;

Fig. 5 is an end elevational view the lower end V being in transverse section substantially on the line 5--5 of Fig. 2;

Fig. 6 is a side elevational view of the spindle and shank member;

Fig. 7 is a perspective .view of. the spindle and shank member taken from the left side of Fig. 6; and

Fig. 8 is a top plan view of the spindle and shank member.

Bit head 9 is of one piece construction having the usual conically formed and threaded extension 10 for securing the same to a reamer body or directly to the drill stem of the rotary drilling apparatus. It also has the usual axial bore 11 (Figs. 3-5) for the flushing fluid which is lined with a renewable wash pipe 12 (Fig. 1), in accordance with established practice, to prevent the head from being cut away by the action of the flushing fluid. The lower end of head 9 (as viewed from the side, Figs. 1 and 2) provides a shallow,

flaring, generally U-shaped recess 13, in which of flush water bore 11. The cutter units A, B are inserted axially into the lower end of the bit head after the manner disclosed in my aforesaid Patent No..1,636,665, and may be securely held in place by nuts 15 in threaded engagement with the ends of shanks b, the bit head having side recesses 16 to receive the nuts and to give access to the shank ends b in applying and removingthe cutter units.

The apparatus heretofore described does not differ from that set forth in myaforesaid patent. In bit heads for drilling small holes of the order of 5 inches in diameter, it. has been dinicult to provide sufiicient bearing surfaces with previously known constructions, including that of my aforesaid patent, to prevent deformation of the head under compression strains with consequent loss of gauge. It has also been diflicult recess 18 to provide a base for shank b.

to drilling operations at great depths, as from 6,000 feet, and to locate the same in the small diameter bit heads without weakening the head or without enlarging the head so as to cause undue wear on the exterior thereof. These difliculties are overcome wholly or substantially in the present invention by the novel configuration and arrangement of the shank and spindle members in the bit head.

As distinguished from the structure of my prior patent the shank and spindle unit 13 isformed with a longer'and heavier base thereby providing a greater spaceor distance between spindle b and shank b'. The larger base comprises a portion or block 17 of substantial thickness with a. fiat upper face (Figs. 6, 7 and 8), one end of the base being cut away to provide a semi-circular recess 18. Base 17 may be extended, however, on the opposite end to an extent equal to When the two spindle and shank units B are mounted in the bit head as shown in Fig. 1 they mutually support one another against compression thrust since faces 19 are disposed in direct abutting engagement.' Bit head 9 provides a socket 20 above the flaring inverted U-shaped recess 13 conforming to the configuration of the assembled base portions 17 of the cutter units, which socket terminates in a transverse fiat wall 21 broken or intersected by bore 11 for the flushing fluid and by parallel bores 14 for spindles b. The semi-circular recess 18 in bases 17 of units B cooperate to form a passage in registry with bore 11 of the bit head and receive therein the lower end of wash pipe 12, as indicated in Fig. 1. Socket 20 is flanked by extensions 22 of the bit head which form rigid abutment walls with ample engaging surfaces positively to prevent any twisting movement of units B within the bit head during the drilling operation. The spindle and shank members B have extensions 23 of stepped configuration integral with the other parts of the unit extending angularly from base portions 1'7 beneath shanks b to provide addi; tional thrust bearing surfaces, the inner faces of the lower erTd of the bit head being made to conform thereto as clearly shown in Figs.

2 and 3. Spindles b project angularly from extensions 23 beneath the thick base portions 17 and are for the most part within vertical projections of shanks b as is apparent from Figs. 6 and 8. By bringing the base portions of spindle and shank units B into direct abutting engagement, the shank portions b' can be broughtcloser together in the present invention than was possible in the arrangement of my aforesaid patent. It is also possible to locate bores 14 for spindles b substantially centrally of the wall of the bit head on opposite sides of flush bore 11 as clearly indicated in Fig. 3, thus permitting a shank of large diameter without making the retaining wall therefor unduly thin on either side. To provide space for nuts 15 and use ofa wrench in setting up and removing the same, the side recesses 16 may be out through into the flush water bore 11 as clearly shown in Figs. 1, 2, and 4.

From the above it will be apparent that the present invention provides such large bearing and thrust surfaces that deformation of the walls of the bit head under compression and thrust strains is prevented even in a bit head of small diameter, that with the new form of bearing base in which the supports f 2r the cutters have portions in direct abutting relationa new thrust area is provided with each change in the cutting units, and that the new formation and arrangement of the cutting units in the bit head permits the location of the shank inwardly toward the axis of the bit so that in the event of undue wear upon the exterior of the bit head the shank members will not be exposed.

While the invention has been herein disclosed in what is now considered to be a preferred form, it is to be understood that the invention isnot limited to the specific details thereof but covers all changes, modifications, and adaptations within the scope of the appended claims.

it is of course obvious that, while frustoconical rollers are shown in the drawings, other forms may be substitutedtherefor, including cylindrical shapes by merely changing the angle. of the axis of the spindle in relation to the axis of the bit head.

I claim as my invention:

1. In earth boring apparatus, in combination, a one-piece bit head having a" central axial bore for flushing fluid, a substantially inverted U-shaped recess at its lower end and a socket above said recess terminating in a transverse wall, said head having bores on either side'of said axial bore in substantial parallelism therewith, said head also having side recesses in spaced relation to said transverse wall and communieating with said side bores and extending through to said axial bore.- cutter carrying units having portions in abutting engagement with each other and cooperating to fit said'socket, shanks on said units extending into said side bores of said head, spindles on said units carrying cutters disposed in said U-shaped recess, and means in said side recesses engaging said shanks for detachably securing said units to said head.

i 2. In earth boring apparatus, in combination, a one-piece bit head having one transverse dlmension greater than the other, said head having an axial bore therethrough for flushing fluid and short bores in substantial parallelism with said axial bore and on opposite sides of the latter in said greater transverse dimensional portion, said head having a socket in its lower end communicating with all of said bores, and roller cutter carrying units having bases in abutting relation cooperating to fit said socket and shanks extending into and secured in said short bores, said head having extending portions shaped to form a substantially inverted U-shaped recess, in which recess the cutter parts of said units are disposed.

3. In earth boring apparatus, in combination, a one-piece bit head having one transverse dimension greater than the other, said head having an axial bore therethrough for flushing fluid and short bores in substantial parallelism with said axial bore and on opposite sides of the latter in said greater transverse dimensional portion, said head having. a socket in its lower end communicating with all of said bores, and roller cutter carrier units having bases in abutting relation with each other cooperating to engage the entire peripheral area of said socket and shanks extending into and secured in said short bores, said bases having recesses cooperating to form an extension of said axial bore in said head, said head having extensions forming a substantially inverted U-shaped recess, in which recess the cutterpai'ts of said units are disposed.

4. In earth boring apparatus, a bit head, a plurality of roller cutter carrier members in said bit head, each carrier member comprising a base ing cut away at one end to provide an arcuate recess and having a rounded extension at the op-- posite end, a shank extending vertically from said I rounded portion of said block. a stepped angular extension projecting angularly from said block beneath said shank and a spindle projecting angularly from the lower face of said extension within a vertical projection 'of said shank and disposing its free end in line with said recess,

the base blocks of the carrier members being in abutting relation with each other.

-' 5. In an earth boring drill, spindles for mountf ing roller cutters thereon and supporting means for said spindles, said means comprising a base portion having'a shank extending upwardly from its outer end and having an angular extension downwardly from which one of the spindles projects, said base portion being'in abutting relationship to another similar base portion.

6. In a roller boring drill, a bit head having a socket in its lower end, depending end walls below the socket, spindles for roller cutters, supporting means for saidspindles confined between said end walls, said supporting means comprising portions abutting each other to resist inward ra-' vial forces, and shanks extending upwardly from said portions in parallel relation to the axis of the bit head for supporting said portions in the bit head.

7. In earth boring'apparatus, a bit head, a: plurality of complementary members for sup-- porting roller cutters in said bit head, said members abutting each other to resist radial compression forces, each of said members comprising a base having a flat upper face, 'a' shank extenda disposed substantially 8. In combination, a bit head having an axial passage for flushing fluid and having a socket at the lower end of the bit head, a plurality of-roll- 'er cutter carrying members supported within said socket, said carrying members having portions in abutting relationship with each other and having .arcuate recesses adjacent the abutting por- 1 tions to provide a flushing fluid passage between the carrying members and in line with the passage in the bit head.

9. In combination, abit head having a socket I at'its lower-end, a renewable wash pipe in-said bit head and extending into said socket, a pair of roller cutter' carrying members supported by. the bit head and disposed within said socket, said carrying members having Dor'tionsadapted to abut'each other and to engage the exterior surface of said wash pipe.

' 10. In earth boring apparatus, a bit head having an axial passage for flushing fluid and having a socket at the lower end of the bit head,

roller cutter carrying means removably supported within said socket and having a bore in alinement with said passage, and. a renewable wash pipe disposed within said passage and extending within said bore into engagement with said carrying means.

CLARENCE E. REED. 

